Drain the oil from the canned tuna and set aside.
Finely chop the onion and bell pepper.
Crack the eggs into a bowl, add salt and pepper, and beat well.
Heat a little cooking oil in a pan and sauté the onion and bell pepper.
Add the tuna and stir-fry together.
Pour in the beaten eggs and cook over low heat, stirring gently until set.
Transfer to a plate and serve.